1. Field of the Invention
The instant disclosure relates to a lighting device; more particularly, to a lighting device having a heat dissipating structure capable of alleviating heat accumulation for both the light source and the optical color wheel thereof.
2. Description of Related Art
For conventional lighting devices, heat dissipation is designed primarily for light-emitting diode (LED) to reduce its working temperature. However, heat around the optical color wheel for light mixing often cannot be dissipated effectively. Also, the light projection angle is fixed for conventional lighting devices, meaning the light pattern is restricted. In use, such lighting devices are limited in scope, and the color temperature of the light are fixed also.
Hence, to address the above issues, the inventor presents the following solution.
The instant disclosure encompasses a lighting device, which can dissipate heat generated by a light source and an optical color wheel.
In one aspect, since the optical color wheel is in rotatable contact with the base, the fins of the base can dissipate heat generated by the optical color wheel in addition to the light source. Besides, the lens is movably disposed on the base, the light projection angle can be adjusted accordingly. Also, a plurality of colored petals can be disposed on the optical color wheel. When the optical color wheel rotates, light passes through different color petals to provide multiple colors of light. Hence, the color temperature of the light for the lighting device can be adjusted.
In order to further appreciate the characteristics and technical contents of the instant disclosure, references are hereunder made to the detailed descriptions and appended drawings in connection with the instant disclosure. However, the appended drawings are merely shown for exemplary purposes, rather than being used to restrict the scope of the instant disclosure.
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The holder 10 receives the base 40 therein. The base 40 has a plurality of protruded fins 48 for heat dissipation. The light source 70 is received inside the base 40, and the optical color wheel 50 is disposed over the light source 70 and rotatably in contact with the base 40. The lens 30 is movably disposed over the base 40 and the optical color wheel 50. An opening 41 is formed centrally on the base 40 to permit passage of light emitted from the light source 70. A central point of the opening 41 is located on an optical axis defined by the lens 30. The optical color wheel 50 is disposed above the opening 41. Through the opening 41, light from the light source 70 pass through the optical color wheel 50 to provide the colored light. The colored light then passes through the lens 30 to form a light beam. The lens 30 can move along an optical axis L to increase or decrease the distance between the lens 30 and the light source 70, thereby changing the light beam characteristics.
In use, heat is generated by the light source 70 for the lighting device 100. A coating, which could be made of wavelength conversion (modifying) material, can be coated on the optical color wheel 50. The light emitted by the light source 70 excites the wavelength conversion material to generate the colored light. Also, as light from the light source 70 passes through the optical color wheel 50, the coating made of a wavelength conversion material (e.g. phosphor powder) coated on the optical color wheel 50 is excited to generate heat. For both conditions, the generated heat can be dissipated by the fins 48 of the base 40. Three different color petals 51, 52, 53 can be disposed on the optical color wheel 50. The optical color wheel 50 is mounted on a shaft 62 of the motor 60 offset from the optical axis L, so only a portion of the optical color wheel 50 is exposed at the opening 41. By controlling the rotation of the shaft 62 of the motor 60, the color petals 51, 52, 53 would rotate sequentially above the light source 70. When light from the light source 70 passes through different color petals 51, 52, 53, multiple colors of light are generated (e.g. a blue LED can excite yellow phosphor powder to produce a white light). Also, the rotational speed of the motor 60 can be controlled to perform light mixing. The base 40 and the optical color wheel 50 are received in the holder 10, wherein screws 18 are used to secure the base 40 to the holder 10. The cover 20 is disposed at the upper edge of the holder 10, combines with the base 40, and covers the optical color wheel 50. Detailed structural descriptions for each element are given below.
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The cover 20 includes a mating portion 22 and a covering portion 24. The mating portion 22 is ring-shaped and connects to the covering portion 24. The mating portion 22 can be removably attached to the base 40. In other words, the mating portion 22 has a ring-like structure for mating to an outer periphery of the base 40. More specifically, the mating portion 22 is mated to the outer periphery of the support portion 44 of the base 40. The covering portion 24 extends outwardly from the periphery of the mating portion 22, having an arched shape to cover a section of the optical color wheel 50 (section not at the base 40). When the mating portion 22 is mated to the support portion 44, the covering portion 24 covers the optical color wheel 50 for protection.
The light source 70 may include a plurality of light-emitting diodes (LED) 72 and a circuit board 74. The LEDs 72 are disposed on the circuit board 74 by the method of surface mount technology (SMT). The circuit board 74 is disposed on the bottom board of the body 42 of the base 40.
For the lighting device of the instant disclosure, the optical color wheel can establish thermal contact with the base. Thus, asides from heat dissipation for the light source by the fins of the base, heat due to light reacting with the optical color wheel can also be dissipated. In addition, since the lens is movably disposed on the base, the projection angle or light shape can be adjusted accordingly. The optical color wheel can be spun and include a plurality of color petals. By spinning the optical color wheel, the light pass through different color petals to provide multiple colors of light. Thus, the color temperature of the light of the lighting device can be adjusted.
The descriptions illustrated supra set forth simply the preferred embodiment of the instant disclosure; however, the characteristics of the instant disclosure are by no means restricted thereto. All changes, alternations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the instant disclosure delineated by the following claims.
Number | Date | Country | Kind |
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201010607098.9 | Dec 2010 | CN | national |